In previous Fedora 12 spotlight blogs we’ve highlighted SystemTap and desktop enhancements. Fedora 12 also includes a number of virtualization improvements, from better virtual disk performance and storage discovery to hot changes for virtual network interfaces, reduced memory consumption and a modern network booting infrastructure. For a more in-depth look, read the collection of interviews here with members of the Fedora community who have worked directly on the many virtualization improvements in Fedora 12.
Libguestfs and guestfish make their debut in Fedora 12 and continue Fedora’s long-standing leadership in making it easier for system administrators to manage virtual machines. Libguestfs is a library for accessing and modifying the disk images of virtual machines. In combination with guestfish, the libguestfs interactive shell replaces the old and cumbersome methods of accessing guest disk images creating loopback mounts as root, using kpartx, and reconfiguring LVM. The libguestfs feature lets administrators work directly with virtual guest machine disk images without any of these steps, and without booting those guests.
New higher-performance virtualization capabilities help administrators build more secure, powerful, scalable and easy to manage solutions. In Fedora 12, administrators can now choose to use huge page backed memory to reduce memory consumption and improve performance by reducing CPU cache pressure, retain VM hardware profiles across qemu upgrades, add network interfaces to a KVM guest without restarting, and enable VM hosts to discover new SAN storage and issue NPIV operations.
Several changes have been introduced to QEMU/KVM virtual machines in an effort to improve host security in the event of a flaw in the QEMU binary, and the deprecated etherboot PXE booting infrastructure has been replaced by gPXE. Fedora 12 also features improvements in the I/O performance of virtual machines using the qcow2 disk format, as well as improved tools for interface configuration.
Check out the video below, where Fedora Project Leader Paul Frields talks about a few of the Fedora 12 virtualization features with Red Hat’s Chris Wright, principal software engineer, and Hugh Brock, manager, Software Engineering.